Wheel.



NITEKD STATES Patented February 21, 1905.

' ATeNr Fries,

WHEEL.

SPECIFICATIONforming part of Letters Patent Dld-783,294, dated February2-1, 1,905.

Application filed April 30, 1904. Serial No. 205,786.

To all whom, it may concern;

Be it known that LEDWIN C. MADDEN, a citizen of the United States, residing in Washington, District of Columbia, have invented cerywheels designed more particularly for use ou rallways or hard roadways and 1n connection with vehicles embodying resonant material, such as metal, in their construction, the objects of the invention being to reduce as much as possible the noise due to vibrations set up in the resonant material of the track or vehicle by Contact of the wheel-rims or treads with the track or with irregularities in the track.

To these ends the invention contemplates the employment of wheels for the vehiclerims or tread portions of ordinary construction in so far as peripheral contour is concerned, with hub portions on the axle projecting into proximity to the rims and confined between face-plates rigid with the rims, but not contacting with the axle, the space between the periphery of the hub portion of the structure and the inner face of the rim being filled with a non-resonant material. The space between tliehub portion and rim conforms throughout the greater portion of its extent to the contour of the wheel; but at suitable points the rim and hub portions are provided with relatively large projections and corresponding recesses around and into which the non-resonant material passes, so as to completely separate the two in so far as the transmission of noisevibrations is concerned; but at the same time the maximum strength is afforded bothto resist direct downward pressure or vehicle weight or to resist the tendency vof the parts to creep one upon the other under the influence of draft or braking strains.

In the accompanying drawings, Figure 1 is a vertical section through a car-wheel em- The letter A. in said drawings indicates onel end of a car-axle having mounted thereon in the manner 1n whichv wheels are usually mount- `ed the hub portion or central section B of the wheel embodying the present invention. This hub portion or central section B may be solid,

as shown, or of any usual section to insure the l rigidity of the wheel and necessary strength of attachment to the axle. The periphery of the section B throughout the major portion of its circumference is concentric, as at I); but between such concentricasections are relatively large recesses b', curving inwardly. The width of the periphery isvpreferably as wide as possible to aord an extended bearing-surface.

The rim C of the wheel is preferably formed in an integral casting having the usual peripheral tread contour, and at one side the said rim is provided with a face-plate c, having an inner radial face adapted to fit against one face of the central section B. A central opening c in the face-plate provides for the passage of the axle without liability of contact between the aXle'and face-plate. The inner peripheral surface of the rim conforms in contour to the periphery of the central section-that is to say, it has major concentric faces B and inwardly-extending projections B2, thus forming between the interior of the rim and periphery of the central section aspace of practically uniform cross-section throughout. rIhis space is filled with a non-resonant material, such as rubber,(indicated.at 1),) which material when soft is put in under sucieutcompression to support the vertical weight and resist Wear and tear without material distortion of the wheel; but at the Sametime sucient elasticity is adorded to prevent the transmission of sound-vibrations from the rim to the body ofthe vehicles or axle and wheel-I ally broken by the non-resonant material, and

although a certain degree of elasticity exists between the parts of the wheel the structure is such that the `wheel is not weakened. The

` contour-lines of the surfaces contacting with the resonant material aresuch that. a greatlyextended bearing-surface is always in action.

In other words, the non-resonant material is subjectedto an almost uniform compression over a wide area, with no tendency to shear i The shape of the or localize the strains. recesses and projections is such that radial movement of the rim compresses the non-v resonant material to practically the same degree that it is compressed in the concentric portions, and at the same time the recesses and projections are of ample-size to insure the necessary strength to resist draft andbraki-ng strains without injury to the nonresonant material. Under n'o circumstances can the rim and wheel. center creep with respect to each other, `and the body orcrosssection of the non-resonant material is preferably such that even should `it wear or brush 1 down to a considerable extent the usefulness of the wheel as a means to carry and control the vehicle `would not be impaired, inasmuch as the rim and center of the Wheel cannot twist out of their proper planes nor rotate withrespect to each other, even though no non-resonant material were present.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is*

1. A wheel for preventing the transmission of sound-variations between the road and' `t'he'vehicle-body, yembodying a center section rim conforming to the peripheral contour'of the' center-section, a non-resonant material interposed between the center section and rim and filling the Vspace between the two, and face-plates secured to the rim and extending inwardly into proximity -to the axle, said plates having radial inner faces in contact with rthe sides of the 'center section, substantially asdescribed. i v Y 2, A non-resonant Wheel for vehicles embodying a rim having its inner surface in concentric sections ,separated by inwardly-extending projections, ar center section having peripheral concentric 'sections and recesses corresponding` in contour to the inner contour of the rim, non-resonant material interposed between the two sections, face-plates rigidv on the rim and embracing the center section and securingbolts for one of the plates, located in the projections of the rim; substantially as described.

' EDWIN C. MADDEN. Witnesses:

ARTHUR M. TRAVERS, HARWooD M. BACON. 

